This invention relates generally to the production of kinescopes and particularly, to a system for removing shadow mask assemblies from kinescope panels of various sizes.
Kinescopes for color television receivers include a screen composed of phosphors which emit light of different colors when impacted by electrons. During the production of the screens, a phosphor slurry is coated onto the entire inside surface of the panel which supports the screen. The excess slurry is removed and a shadow mask assembly is inserted into the panel. The phosphor is then exposed to light through the apertures in the shadow mask. The shadow mask assembly is then removed and the unexposed slurry washed away leaving the lightexposed phosphor in the desired location. This process is then repeated for the phosphors of the other two colors. Accordingly, during the production of the screen, the shadow mask assembly is frequently removed from and inserted into the panel. This continual removal and insertion is a labor intensive and expensive operation and frequently results in damage to the shadow mask assembly.
Prior art attempts at automating the shadow mask assembly removal operation have had limited success because typically the automatic removing equipment is capable of removing the shadow mask assemblies from a very limited number of panel sizes. Accordingly, when automatic removal is utilized, a change of panel size typically requires changing the mask removing equipment.
For these reasons, there has long been a need for a system which is capable of removing shadow mask assemblies from panels of many sizes as the panels proceed along a production line in random order.
The instant invention overcomes the above difficulties and solves the long felt need by the provision of a system for removing shadow mask assemblies from kinescope panels of varying sizes. The system automatically senses the size of the panel and centers the panel so that shadow mask assemblies can be removed from panels which flow along the production line in random order of size.